Is it reasonable to use Neo as a baseline? Modern Starlink satellites can weigh 800kg, or less than 20% of Neo. I see discussions suggesting they generate ~73kw for that mass. I guess because they aren't trying to blanket an entire continent in signal? Or, why are they so much more efficient than Neo?
Interestingly the idea of doing compute in space isn't a new one, it came up a few years ago pre-ChatGPT amongst people discussing the v2 satellite:
Still, you make good points. Even if you assume much lighter satellites, the GPUs alone are very heavy. 700kg or so for a rack. Just the payload would be as heavy as the entire Starlink satellite.
You can't increase the size of the radiator and reduce the mass of the satellite. How is that supposed to work?
You're also forgetting that Starlink satellites aren't in a sun synchronous orbit which means they have to overbuild the energy generation capacity (low capacity factor) and can simultaneously take advantage of earth's shadow to cool down.
Droplet radiators can theoretically do this. The radiator is made up of extremely fine liquid droplets expelled from what is basically a big space shower head. The droplet cloud has a big surface area so more heat can radiate. The droplets are collected in a sort of drain the other side. The idea has been around for decades but there are lots of practical problems to work out, like minimizing losses due to splashes or droplets heading in the wrong direction (e.g. using ferrofluids and magnetic containment). It's never been worked on seriously because conventional radiators were always enough.
With droplet radiators increasing the effective size means using a bigger head/drain and longer booms to expand the distance between them, so the scaling properties are different to pipe based radiators.
Is it reasonable to use Neo as a baseline? Modern Starlink satellites can weigh 800kg, or less than 20% of Neo. I see discussions suggesting they generate ~73kw for that mass. I guess because they aren't trying to blanket an entire continent in signal? Or, why are they so much more efficient than Neo?
Interestingly the idea of doing compute in space isn't a new one, it came up a few years ago pre-ChatGPT amongst people discussing the v2 satellite:
https://forum.nasaspaceflight.com/index.php?topic=58374.msg2...
Still, you make good points. Even if you assume much lighter satellites, the GPUs alone are very heavy. 700kg or so for a rack. Just the payload would be as heavy as the entire Starlink satellite.